Next week, the iPhone will launch on three additional U.S. regional carriers. This move follows last month’s roll out to five regional carriers plus last year’s addition of C Spire and Puerto Rico-based Claro Puerto (Apple’s first deasl with regional carriers).

Apple’s regional expansion prompted Morgan Stanley analyst Katy Huberty to issue a note to investors saying that the new partnerships will help ensure sustained iPhone growth. She also noted that she doesn’t expect to see carriers dropping subsidized pricing for the iPhone – a concern that has also made investors hesitant when it comes to Apple.

Earlier this month, five regional U.S. carriers announced that they would begin carrying the iPhone 4 and 4S. All were offering the devices at $50 less than the standard list prices of the larger national carriers (AT&T, Verizon, and Sprint). All five carriers are in more rural areas of the country that aren’t well served by the national carriers. Two are in Alaska, for example.

Most news about the iPhone in the U.S. is centered around the major national carriers including those that offer the iPhone (AT&T, Verizon, and Sprint) and T-Mobile, which doesn’t.

Today, however, that news focuses on Virginia-based carrier nTelos, which will become the second smaller carrier in the U.S. to offer the iPhone. Seeking to differentiate its iPhone options from the larger carriers, nTelos is also offering some sweet deals on the purchase of an iPhone 4/4S as well as a bargain price for unlimited data.